The present invention relates to fuel pumps of the type adapted to be utilized with internal combustion engines. In particular, the invention is directed to fuel pump governors, and especially to a flexible governor drive which allows for smoother governor operation.
It is known in the art to provide a pump governor to maintain the desired engine speed within the operating range under various load settings. Pumps of this type can be seen, for example, in U.S. Pat. Nos. 3,247,799 and 3,288,124. In mechanical governors such as these, governor weights acting against a governor thrust sleeve rotate a metering valve by means of a governor linkage to vary the setting of the metering valve. The governor weights are pivotally retained in an annular weight retainer member which in turn is mounted on a hub member for rotation therewith. The hub member is mounted on the pump rotor.
In an effort to absorb torsional loading and vibrations transmitted to the pump from the engine as well as those created within the pump itself, it is known to provide a flexible thermoplastic retaining ring which connects the governor weight retainer member to the hub member. The intended purpose of such a retaining ring is to provide smooth governor operations, but the prior art units have failed to provide satisfactory results. The smoothness of operation desired has not been realized and frequently the thermoplastic retaining rings have ruptured or deteriorated causing complete pump failure or extremely irregular engine operation.
Use of mechanical assemblies containing resilient elements, such as coil springs, in place of the thermoplastic retaining rings for providing a flexible connection between the weight retainer member and the hub member have been attempted but without achieving the desired results.